When soft tissue tears away from bone, reattachment becomes necessary. Various devices, including sutures alone, screws, staples, wedges, and plugs have been used in the past to secure soft tissue to bone.
Recently, various types of threaded suture anchors have been developed for this purpose. Some threaded suture anchors are designed to be inserted into a pre-drilled hole. Other suture anchors are self-tapping.
U.S. Pat. No. 4,632,100 discloses a cylindrical threaded suture anchor. The suture anchor of the '100 patent includes a drill bit at a leading end for boring a hole in a bone, followed by a flight of threads spaced from the drill bit for securing the anchor into the hole created by the drill bit. U.S. Pat. No. 5,370,662 discloses a suture anchor having a flight of threads which extend to the tip of the anchor. U.S. Pat. No. 5,156,616 discloses a similar suture anchor having an axial opening for holding a knotted piece of suture.
All of the above-noted suture anchors include structure for attaching the suture to the anchor. U.S. Pat. No. 4,632,100, for example, discloses and claims a press-fitted disc and knot structure which secures the suture to the anchor. In other suture anchors, such as those disclosed in U.S. Pat. No. 5,370,662, the suture is passed through an eyelet located on the proximal end of the anchor. U.S. Pat. No. 5,152,790 discloses a suture anchor with a rotatable ring for securing suture to the suture anchor.
The devices discussed above are fairly time consuming and complicated to fasten the soft tissue against the bone mass. It is also difficult for these devices to keep the soft tissue tightly attached to the bone mass during the body's healing process.
It would therefore be an advantage to provide a suture anchor that simplifies the operation process and effectively secures the soft tissue against the bone mass during the body's healing period. Preferably, the suture anchor will be provided with an eyelet that is movable with respect to the anchor in order to simplify the process of attaching a suture to the eyelet.